The present invention relates to apparatus and methods for freeing seized bolts and, more particularly, to an air hammer bit that may loosen seized bolts by impacting bolt head centers.
Presently, there are many components in the automotive industry and elsewhere that are being manufactured from lightweight metals, especially aluminum, because of its weight and strength. Steel bolts, however, continue to be used as fasteners for these components. When steel bolts pass through or are threaded into aluminum or other lightweight metal parts, the steel bolts can become seized over time due to galvanic reactions between the two different metals. These bolts often become difficult to remove usually resulting in damage to the bolt or to the component. Frustrated technicians will strike the head of a seized bolt with a punch or hammer in an attempt to loosen them.
Pneumatic hammers have also been used with a punch bit, usually resulting in the bit jumping off the bolt head and damaging the hex head of the bolt, making it hard to fit a wrench or socket to it again. The majority of the impacts from these punch bits hit squarely on the head of the bolt, transferring the shocks to the metal at the circumferential base of the bolt head, greatly absorbing and reducing the effect of the impact force instead of concentrating impacts on the center of the bolt head, where the impacts may be more effective in being transferred to the shank and threads of the bolt, thereby breaking up rust and corrosion. Many components in the automotive, construction and other fields are ruined due to failed attempts to extract seized bolts. Parts replacement and labor costs increase as a result.
As can be seen, there is a need for a tool that may apply an impact on the center of a bolt head without slipping off the bolt head and damaging the bolt.